The present invention relates generally to seat restraint systems for vehicles and, more particularly, to a pass through seat restraint tension sensing assembly for a seat restraint system in a vehicle.
It is known to provide a seat restraint system such as a seat belt in a vehicle to restrain an occupant in a seat of the vehicle. In some vehicles, the seat restraint system may be a lap belt, a shoulder belt, or both. Typically, the lap belt and shoulder belt are connected together at one end. The seat restraint system includes a latch plate at the connected end. The seat restraint system also includes a buckle connected at one end by webbing or the like to vehicle structure. The buckle receives the latch plate to be buckled together. When the buckle and latch plate are buckled together, the seat restraint system restrains movement of the occupant to help protect the occupant during a collision.
Smart inflatable restraint systems need to know what is occupying a seat of the vehicle. Decisions on deployment of inflatable restraints depend on information supplied by sensors in the seat in determining weight of an object in the seat. When a child seat is placed in the seat and cinched down, the sensors may read a large mass instead of a child seat. With this condition, however, there will be high tension in the seat restraint system. Comfort studies have shown that no human occupant would wear their seat restraint that tight. With this information on seat restraint tension, the inflatable restraint system can decide on deployment of the inflatable restraint.
Therefore, it is desirable to provide a pass through seat restraint assembly for sensing tension in a seat restraint system of a vehicle. It is also desirable to provide an assembly for a seat restraint to pass through for a seat restraint system in a vehicle that allows a control module to determine the difference between either a child seat and a small occupant. It is further desirable to provide an assembly for a seat restraint to pass through for a seat restraint system in a vehicle that provides information used in determining inflatable restraint deployment levels.
It is, therefore, one object of the present invention to provide for pass through seat restraint tension sensing in a seat restraint system of a vehicle.
It is another object of the present invention to provide a Hall effect sensor and balanced force for pass through seat restraint tension sensing in a seat restraint system of a vehicle.
To achieve the foregoing objects, the present invention is a pass through seat restraint tension sensing assembly for a seat restraint system in a vehicle including a housing for allowing seat belt webbing of the seat restraint system to pass therethrough. The pass through seat restraint tension sensing assembly also includes at least one spring disposed in the housing and at least one magnet disposed in the housing. The pass through seat restraint tension sensing assembly includes a Hall effect sensor disposed in the housing and cooperable with the at least one magnet. The pass through seat restraint tension sensing assembly further includes a movable actuator disposed in the housing and cooperable with the belt webbing and the at least one spring to move the at least one magnet relative to the Hall effect sensor to indicate a tension level in the seat restraint system.
One advantage of the present invention is that a pass through seat restraint tension sensing assembly is provided for a seat restraint system in a vehicle. Another advantage of the present invention is that the pass through seat restraint tension sensing assembly senses tension in the seat restraint system to help identify what is occupying the seat, either a child, child seat, or low mass adult. Yet another advantage of the present invention is that the pass through seat restraint tension sensing assembly has Hall effect sensors in a pushxe2x80x94push arrangement to maximize the output of the Hall effect sensors. Still another advantage of the present invention is that the pass through seat restraint tension sensing assembly employs two springs that are displaced one half the distance from center and one spring on the other side of center for maximum balance force with three springs to balance out-of-plane loading. A further advantage of the present invention is that the pass through seat restraint tension sensing assembly passes the force through at high loads and does not carry the load, resulting in the assembly not being directly in the tension path at very high loads. Yet a further advantage of the present invention is that the pass through seat restraint tension sensing assembly has a balanced force relationship provided by offset springs that prevents internal tipping of an actuator. Still a further advantage of the present invention is that the pass through seat restraint tension sensing assembly has springs that require {fraction (1/10)} the force to generate the maximum load and are out of the load path at the maximum load (5000 lb). Another advantage of the present invention is that the pass through seat restraint tension sensing assembly is universal because it utilizes common dimensions such as width and thickness of all seat belt restraints, can be formulated from light weight and plastic components, and is relatively low cost. Another advantage of the present invention is that the pass through seat restraint tension sensing assembly has a force/deflection relationship that is non-linear and allows more resolution at lower forces and does not rattle, but provides low tension output.
Other objects, features, and advantages of the present invention will be readily appreciated, as the same becomes better understood, after reading the subsequent description taken in conjunction with the accompanying drawings.